AT Command Set

turns to the AT command mode.

3.There are various options to switch from data mode to command mode:

a)Escape sequence +++

b)Circuit 108/2 (DTR) changes from ON to OFF, reaction depends on command at&d (caution if AT&D0: TA ignores status on DTR).

c)The message Modem Status Command (MSC) for control channel is defined by the multiplexer protocol GSM07.10. MSC conveys V.24 signals. Bit 3 of Control Signal Octet is DTR, reaction depends on command at&d (caution if AT&D0: TA ignores status on DTR).

4.The parameter maximum frame size (N1) of AT+CMUX in GSM07.07 is fixed to 97 and cannot be changed. All other parameters are not avail- able.

5.Multiplex mode can be terminated by AT^SMSO (,AT^SMSO Switch off mobile station" pg. 191). It has to be reestablished after power-on.

4.28.1Restricted use of AT commands in Multiplex mode

In Multiplex mode, the operation of several AT commands varies from the normal mode. This chapter summarizes the concerned commands. For general rules and restrictions to be considered in Multiplex mode please refer to [5].

Data, fax and GPRS calls can only be set up on logical channel 1. Due to this restriction, AT com- mands have a different behaviour on channels 2+3 compared to channel 1. Several commands are not available, others return different responses. These commands are listed in the table below:

Table 6: Availability of AT commands on virtual channels

 

 

 

 

Command

Behaviour on channel 1

Differences on channel 2+3

+++

as described

not usable

ATE

as described

as described

AT+CBST

as described

not usable

AT+CR

as described

not usable

AT+CRLP

as described

not usable

AT+CG... (GPRS commands)

as described

usage not recommended 2)

AT+F.... (Fax commands)

as described

not usable

AT&C

as described

not usable

AT&D

as described

not usable

AT&F

as described

data call parameters not changed

 

 

S3, S4 not changed

 

 

 

AT&S

as described

not usable

AT&V

as described

data call parameters not displayed

ATA

as described

no data calls

ATD

as described

no data calls

ATDI<n>

as described

not usable

ATO

as described

not usable

ATS0 1)

as described

not usable

ATS3 1)

as described

as described

MC35_ATC_01_V04.00

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Siemens MC35 Restricted use of AT commands in Multiplex mode, Command Behaviour on channel Differences on channel 2+3, Ate
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MC35 specifications

The Siemens MC35 is a compact and versatile modem designed primarily for mobile communication, data transmission, and machine-to-machine (M2M) applications. Launched in the early 2000s, it quickly became popular due to its blend of performance, reliability, and ease of integration, making it a solid choice for developers and businesses.

One of the key features of the MC35 is its support for GSM and GPRS technologies. This allows it to connect seamlessly to various networks, enabling users to transmit data at speeds that were impressive for its time. The GPRS capability can offer data rates of up to 171.2 kbps, allowing for efficient data transfer even in areas with limited connectivity.

The MC35 is designed to support both SMS and voice functionalities, making it adaptable for a range of applications. This includes remote monitoring, telemetry, and alarm signaling. The ability to send and receive SMS messages is a significant advantage for applications that require immediate alerts and notifications, enhancing its utility in security systems and industrial automation.

Furthermore, the modem is equipped with a range of interfaces, including serial communication (RS232), which makes it compatible with various hardware devices. This facilitates easy integration into existing systems, whether for industrial machinery or consumer electronics. Additionally, it features a robust software development kit (SDK), which enables developers to create custom applications tailored to their specific requirements.

Power consumption is another notable characteristic of the Siemens MC35. It is engineered to be energy-efficient, which is especially important for battery-operated devices or systems that require a prolonged operation without frequent recharging or maintenance.

In terms of physical characteristics, the MC35 is compact and lightweight, allowing it to fit into various enclosure designs without occupying much space. Its durability ensures it can perform reliably in different environments, making it suitable for outdoor and industrial applications.

To summarize, the Siemens MC35 stands out as a reliable modem with a rich feature set that includes GSM and GPRS support, SMS and voice capabilities, easy integration through various interface options, and energy-efficient operation. Its adaptability makes it a valuable tool for a wide array of communication and data transmission tasks, solidifying its place in the evolution of mobile communications technology.
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